OBJECTIVES: To investigate the impact fordadistrogene movaparvovec may have on physical functioning based on the Pediatric Outcomes Data Collection Instrument (PODCI).

METHODS: Ambulatory boys with DMD, aged 4-12 years who received fordadistrogene movaparvovec, a gene therapy, in a phase 1b, multicenter, single-arm, open-label trial (NCT03362502) were evaluated by PODCI. The parent/caregivers completed this patient-reported outcomes assessment of musculoskeletal health. For each core scale and the global functioning scale (GFS), individual item responses were transformed to normative scores, where higher scores represent better physical functioning and psychological well-being. The observed score and the change from baseline (CFB) for each domain and the GFS were summarized for this study and a similar external control cohort derived from another DMD trial (NCT02310763).

RESULTS: Nineteen ambulatory boys received fordadistrogene movaparvovec (n=3 low-dose, n=16 high-dose). For the transfer and basic mobility core scale, participants treated with fordadistrogene (high-dose) and the external control (n=13) showed a mean±SD CFB of -1.8±14.0 and -14.7±19.9 (median 0.0 vs -12.0, Wilcoxon exact test p=0.048), respectively at 1 year. For the sports and physical functioning core scale, treated and external control showed a mean±SD CFB of -0.13±18.5 and -13.5±16.6 (median -0.1 vs -8.2, p=0.067), respectively. The GFS had a mean±SD CFB of 1.7±13.4 in high-dose treated group compared to the external cohort, -13.6±17.9 (median 0.5 vs -9.5, p = 0.012). No difference was observed between the groups at baseline in these scores.

CONCLUSIONS: Preliminary PODCI results indicate fordadistrogene movaparvovec has the potential to stabilize or improve physical functioning and psychological well-being in ambulatory DMD patients. The transfer and basic mobility core scale and the sports and physical functioning scale are key core scales that accurately capture a patient’s PODCI score.